netfs: zero the tail of a short DIO/unbuffered readgrafted

The buffered read collector zero-fills the tail of a short read that
stops below the inode's i_size (netfs_clear_unread()), so a read that
races an extending write still returns the expected number of bytes.
The non-buffered collector path does no such thing: it just records
how much was transferred.

Add the same zero-fill for the non-buffered case, gated on
NETFS_SREQ_CLEAR_TAIL: a subreq's source sets that flag when a short
result from it is known to be safe to treat as a hole, as opposed to
NETFS_SREQ_HIT_EOF, which means the read genuinely ran off the end of
the file and should be reported short as-is. Only CLEAR_TAIL should
zero-fill here; a real EOF must stay a real short read.

No source currently sets CLEAR_TAIL on an unbuffered/DIO subrequest,
so this is inert on its own -- a following change teaches cifs to set
it in the one case that needs it.

Fixes: e2d46f2ec332 ("netfs: Change the read result collector to only use one work item")
Reviewed-by: David Howells <dhowells@redhat.com>
Reviewed-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Ronnie Sahlberg <ronniesahlberg@gmail.com>
Cc: Shyam Prasad N <sprasad@microsoft.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Bharath SM <bharathsm@microsoft.com>
Cc: stable@vger.kernel.org

1 files changed, 25 insertions, 0 deletions

diff --git a/drivers/net/ipa/Makefile b/drivers/net/ipa/Makefile
new file mode 100644
index 000000000..e148ec3c1
--- /dev/null
+++ b/drivers/net/ipa/Makefile
@@ -0,0 +1,25 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the Qualcomm IPA driver.
+
+IPA_REG_VERSIONS	:=	3.1 3.5.1 4.2 4.5 4.7 4.9 4.11 5.0 5.5
+
+# Some IPA versions can reuse another set of GSI register definitions.
+GSI_REG_VERSIONS	:=	3.1 3.5.1 4.0 4.5 4.9 4.11 5.0
+
+IPA_DATA_VERSIONS	:=	3.1 3.5.1 4.2 4.5 4.7 4.9 4.11 5.0 5.2 5.5
+
+obj-$(CONFIG_QCOM_IPA)	+=	ipa.o
+
+ipa-y			:=	ipa_main.o ipa_power.o ipa_reg.o ipa_mem.o \
+				ipa_table.o ipa_interrupt.o gsi.o gsi_reg.o \
+				gsi_trans.o ipa_gsi.o ipa_smp2p.o ipa_uc.o \
+				ipa_endpoint.o ipa_cmd.o ipa_modem.o \
+				ipa_resource.o ipa_qmi.o ipa_qmi_msg.o \
+				ipa_sysfs.o
+
+ipa-y			+=	$(IPA_REG_VERSIONS:%=reg/ipa_reg-v%.o)
+
+ipa-y			+=	$(GSI_REG_VERSIONS:%=reg/gsi_reg-v%.o)
+
+ipa-y			+=	$(IPA_DATA_VERSIONS:%=data/ipa_data-v%.o)